docs: def print_str(self, value, justify_right=True):
          """Print a 4 character long string of values to the display. Characters
          in the string should be any ASCII value 32 to 127 (printable ASCII).
          """
          # Calculcate starting position of digits based on justification.
          pos = (4-len(value)) if justify_right else 0
          # Go through each character and print it on the display.
          for i, ch in enumerate(value):
              self.set_digit(i+pos, ch)